Powergraphy Battery Simulator
Evaluation version 1.00 

1.	INTRODUCTION	1
1.1.	WHAT DOES THIS PROGRAM DO?	1
1.2.	HOW DOES IT WORK AND HOW EXACT IS THE PREDICTION?	2
1.3.	WHAT CAN YOU DO IN ADDITION USING COMMERCIAL VERSION OF THE PROGRAM	2
2.	INSTALLATION	3
3.	"STEP-BY-STEP" GUIDE	3
4.	ANALYSIS DETAILS	4
4.1.	CONSTANT CURRENT	4
4.2.	VARIABLE CURRENT	4
4.3.	CONSTANT LOAD	5
5.	WHAT CAN GO WRONG?	6

1. Introduction
1.1. What does this program do?
Powergraphy battery simulation demo can calculate voltage profile during battery 
discharge/charge under user-defined conditions. That means for example, instead of 
measuring battery discharge profile using battery cycler (expensive and time consuming 
way) you can simply calculate it, which usually takes about 30 second. You can see 
how long the battery will power specific device until it fails, or optimize charging 
conditions. Basically, you can make any experiment with this virtual battery as if you 
had a real one in your hand, but without danger that would kill your device or any 
explosion. 
Demo includes constant current discharge/charge, variable pulse current 
discharge/charge and constant load discharge. Currently the number of battery is 
restricted to 4: Sony Li-ion 18650, Matsushita Li-ion 18650, Hitachi Ni-MH AA size 
and Duracell Alkaline AA size. 

1.2. How does it work and how exact is the prediction?
Numerical image of battery (NIOB) is not a collection of different discharge curves etc. 
Instead, it is a working mathematical model of battery. During the calculation, real 
processes inside the battery are recreated inside your computer. This model is based on 
deep understanding of battery's electrochemistry, supported by several scientific 
publications [ see end of page ]. 
	Important point is that alkaline battery has different behavior from NiCd, even 
if both are AA size and can be plugged in same device. Moreover, even batteries of  
the same type (alkaline, NiCd, NiMH, Lead acid or Li-ion) can be very different. 
That is why characteristic parameters for each particular model of battery are 
obtained using an automatic Powergraphy battery parameterization system. More details 
about Powergraphy battery parameterization initiative can be found in 
http://www.kkpcr.re.kr/powergraphy. 
Precision of the simulation is proved by comparison of predicted voltage 
profiles with really measured ones, and in most cases does not exceed 2%. 
1.3. What can you do in addition using commercial version of the program
Commercial version of the program can be obtained from Korea Kumho 
Petrochemical Co., Ltd.. Check Powergraphy web site about the ordering procedure or 
contact us under following address: (coyoon@mail.kkpcr.re.kr)
	The commercial version of simulation software can simulate any kind of 
battery (provided you have a numerical image of the battery, produced by Powergraphy 
system, downloaded from battery manufacturer web site). It also has a database 
including many of popular battery models. The conditions of simulation are almost 
unlimited. In addition to many predefined conditions (including, for example, 
calculation of Ragone-plot, pulse discharge, constant and variable power discharge, DC 
motor discharge simulation etc.) you can even simulate the behavior of your entire 
device (Notebook, Mobile phone or electric vehicle) without even making it first ? 
using only its schematics.
Several batteries can be put together to form a battery pack. Additional electric 
elements can be added to simulate the behavior of battery-pack safety device.
Several different charge/discharge patterns can be applied to battery one after 
another, just as the battery cycler can do. You can however design loads, which will be 
very difficult if not impossible to measure experimentally, for example different fault 
conditions, including short circuiting batteries or malfunctioning one of the batteries in 
the pack.
Another advantage of commercial version is possibility to visualize processes 
going on inside your battery. During the simulation, the entire information (currents, 
voltages, heat development) about any place inside the battery is available. You can 
actually see the diffusion concentration profiles and voltage distribution across the 
batteries active layer, notice where high current might pose a problem and where battery 
can still be pushed harder.

2. Installation
Open the zip-archive in a temporary directory and run setup.exe. After finishing the 
installation remove all files in this temporary directory, except for this readme file 
which contains additional informatin not present in Help and therefore is usefully copied 
in program directory. 
Notice - 1024/743 is the screen resolution for which this program is designed. If 
resolution is lower, program will be larger then the screen. Otherwise on computers 
slower then k6-2 300 or Pentium-II 300 the simulation can take longer time then 
suggested in Help.

3. "Step-by-step" guide
After starting the "Powergraphy battery simulator" program you can select a battery 
model by pressing a "Battery model selection" button. Select battery from the list and 
press "OK".
From "Analysis" menu you can select analysis you want to perform. Only 
"Basic" analyses are available in demo version. Chose one of "constant current", 
"variable current" or "constant voltage" analysis.
After adapting the analysis options for your needs, press "Run analysis" button. 
It is particularly important to set correct starting voltage. It usually should be equal to 
battery maximal voltage or less. Battery maximal voltage is shown in battery 
description line on Graph caption.
Progress of analysis is approximately shown by "progress indicator" on 
program window. Analysis takes about 30 seconds, depending on discharge time you 
specified.
When analysis is finished, battery voltage vs. time dependence is shown in the 
Graph window. It can be printed by choosing "Print" command in "File" menu.
Voltage vs. time data is saved in program directory as ASCII file named 
"Analys.fig".

4. Analysis details
4.1. Constant current
During this analysis battery is subjected to constant current discharge/charge. Available 
options are:
- Current value
Current at which battery is discharged or charged. Positive current means discharge 
of battery.
- Battery's voltage
Initial voltage of battery when discharge or charge is started. Good value is the one 
specified in "battery description line", or lower. Actual battery voltage will change 
during the discharge corresponding to calculation of internal electrochemical 
processes.
- Duration of analysis
Time interval during which the current is applied to battery
- Time step
Minimal time step which programs make during calculation. Actual time step used 
for printing of results is chosen adaptively and can be larger, if discharge profile is 
smooth.

4.2. Variable current
During this analysis battery is subjected to complex current waveform specified by user.  
Available options are:
- Current waveform pattern is defined by a table, where each row specifies "time" 
and "current" for each key-point of user-defined waveform. Current between the 
points is linearly interpolated, which means that on current vs. time plot each 
specified point would be connected by straight lines. User can change the default 
values arbitrary to match the intended analysis. "Time" should always increase 
from first to last point, whereas "Current" is arbitrary ? it can be negative, positive 
or zero (positive current means discharge). Last specified point should have time 
value equal to duration of analysis. Several points can have same time value, which 
would disable all of them but one. 
- Battery's voltage
Initial voltage of battery when discharge or charge is started. Good value is the one 
specified in "battery description line", or lower. Actual battery voltage will change 
during the discharge corresponding to calculation of internal electrochemical 
processes.
- Duration of analysis
Time interval during which the waveform is applied to battery and voltage response 
is calculated.
- Time step
Minimal time step which programs make during calculation. Actual time step used 
for printing of results is chosen adaptivelly and can be larger, if discharge profile is 
smooth.

4.3. Constant load
During this analysis battery is discharged through a constant resistor.  
Available options are:
- Resistor value
Value of the resistor connected to the battery. Usual battery powered devices have 
values from 10 to 100 Ohm. For example, a DC motor used in toy-train has 
resistance 20 Ohm, and pocket radio ? about 60 Ohm. Set value smaller then 0.1 
Ohm to observe a short-circuit discharge of battery. 
- Battery's voltage
Initial voltage of battery when discharge or charge is started. Good value is the one 
specified in "battery description line", or lower. Actual battery voltage will change 
during the discharge corresponding to calculation of internal electrochemical 
processes.
- Duration of analysis
Time interval during which the waveform is applied to battery and voltage response 
is calculated.
- Time step
Minimal time step which programs make during calculation. Actual time step used 
for printing of results is chosen adaptively and can be larger, if discharge profile is 
smooth.

5. What can go wrong?
Under some unusual load conditions you might experience non-convergence problem 
during analysis. In this case Graph will not show all specified time region or show 
nothing at all. First check in this case, if conditions you specified make sense:
- is "initial voltage" equal or lower then maximal voltage?
- Is "simulation time" not too much longer then expected time of full discharge or 
charge of battery? Try reducing the "simulation time".
If this checking still does not help, try reducing the time step to 0.1 or 0.01.


References
  E. Barsoukov, J. H. Kim, C. O. Yoon, H. Lee, Solid State Ionics, 116, 249 (1999). 
  E. Barsoukov, J. H. Kim, D. H. Kim, K. S. Kim, C.O. Yoon, H. Lee, J. Power. 
Sources, 83, 61 (1999). 
  E. Barsoukov?, J. H. Kim, D. H. Kim, K. S. Hwang,  C. O. Yoon, and H. Lee, 
Journal of New Materials for Electrochemical Systems, (1999) in press


Copyright
Program is copyright by Kumho Chemical Lab., Kumho Petrochemical Ltd. 1999
Distribution of unchanged program package is free and encouraged. Distribution of 
disassembled or changed by any means program package is prohibited and will be
a subject of legal action. Program is distributed _as is_, user takes whole
responsibility of any possible damage which might arise from using this 
program. Kumho Petrochemical will not by liable to any extent for any kind of 
damage arising from use of this program.
Using simulation results in publications, presentations, web-sites
and books is allowed as long as use of the program is acknowledged as follows: 
"Powergraphy Battery Simulator developed in Kumho Chemical Lab., 
Kuhmo Petrochemical Ltd." 
